content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * ---------------
   * KeyHandler.java
   * ---------------
   * (C) Copyright 2003-2008, by Object Refinery Limited and Contributors.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 23-Jan-2003 : Version 1 (DG);
   *
   */
  
  package org.jfree.data.xml;
  
  import org.xml.sax.Attributes;
  import org.xml.sax.SAXException;
  import org.xml.sax.helpers.DefaultHandler;
  
  /**
   * A SAX handler for reading a key.
   */
  public class KeyHandler extends DefaultHandler implements DatasetTags {
  
      /** The root handler. */
      private RootHandler rootHandler;
  
      /** The item handler. */
      private ItemHandler itemHandler;
  
      /** Storage for the current CDATA */
      private StringBuffer currentText;
  
      /** The key. */
      //private Comparable key;
  
      /**
       * Creates a new handler.
       *
       * @param rootHandler  the root handler.
       * @param itemHandler  the item handler.
       */
      public KeyHandler(RootHandler rootHandler, ItemHandler itemHandler) {
          this.rootHandler = rootHandler;
          this.itemHandler = itemHandler;
          this.currentText = new StringBuffer();
          //this.key = null;
      }
  
      /**
       * The start of an element.
       *
       * @param namespaceURI  the namespace.
       * @param localName  the element name.
       * @param qName  the element name.
       * @param atts  the attributes.
       *
       * @throws SAXException for errors.
       */
      @Override
      public void startElement(String namespaceURI,
                               String localName,
                               String qName,
                               Attributes atts) throws SAXException {
  
          if (qName.equals(KEY_TAG)) {
              clearCurrentText();
          }
          else {
              throw new SAXException("Expecting <Key> but found " + qName);
          }
  
      }
  
      /**
       * The end of an element.
       *
       * @param namespaceURI  the namespace.
       * @param localName  the element name.
       * @param qName  the element name.
       *
       * @throws SAXException for errors.
       */
      @Override
      public void endElement(String namespaceURI,
                             String localName,
                             String qName) throws SAXException {
  
          if (qName.equals(KEY_TAG)) {
              this.itemHandler.setKey(getCurrentText());
              this.rootHandler.popSubHandler();
              this.rootHandler.pushSubHandler(
                  new ValueHandler(this.rootHandler, this.itemHandler)
              );
          }
          else {
              throw new SAXException("Expecting </Key> but found " + qName);
          }
  
      }
  
      /**
       * Receives some (or all) of the text in the current element.
       *
       * @param ch  character buffer.
       * @param start  the start index.
       * @param length  the length of the valid character data.
       */
      @Override
      public void characters(char[] ch, int start, int length) {
          if (this.currentText != null) {
              this.currentText.append(String.copyValueOf(ch, start, length));
          }
      }
  
      /**
       * Returns the current text of the textbuffer.
       *
       * @return The current text.
       */
      protected String getCurrentText() {
          return this.currentText.toString();
      }
  
      /**
       * Removes all text from the textbuffer at the end of a CDATA section.
       */
      protected void clearCurrentText() {
          this.currentText.delete(0, this.currentText.length());
      }
  
  }
  